Renormalized energy of ground and first excited state of Fröhlich polaron in the range of weak coupling

Tkach, N. V.; Seti, Ju. O.; Voіtseкhіvsкa, О. М.; Pytiuk, O. Yu.

doi:10.5488/cmp.18.33707

Cited by 8 publications

(8 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The above approaches, however, failed to determine the spectrum of Hamiltonian (1) even in the weak coupling limit [67].…”

Section: Polaron and Fundamental Problems Of Non-relativistic Quantum Field Theorymentioning

confidence: 99%

Translational-Invariant Bipolarons and Superconductivity

Лахно

2020

Condensed Matter

View full text Add to dashboard Cite

A translation-invariant (TI) bipolaron theory of superconductivity based, like Bardeen–Cooper–Schrieffer theory, on Fröhlich Hamiltonian is presented. Here the role of Cooper pairs belongs to TI bipolarons which are pairs of spatially delocalized electrons whose correlation length of a coupled state is small. The presence of Fermi surface leads to the stabilization of such states in its vicinity and a possibility of their Bose–Einstein condensation (BEC). The theory provides a natural explanation of the existence of a pseudogap phase preceding the superconductivity and enables one to estimate the temperature of a transition T * from a normal state to a pseudogap one. It is shown that the temperature of BEC of TI bipolarons determines the temperature of a superconducting transition T c which depends not on the bipolaron effective mass but on the ordinary mass of a band electron. This removes restrictions on the upper limit of T c for a strong electron-phonon interaction. A natural explanation is provided for the angular dependence of the superconducting gap which is determined by the angular dependence of the phonon spectrum. It is demonstrated that a lot of experiments on thermodynamic and transport characteristics, Josephson tunneling and angle-resolved photoemission spectroscopy (ARPES) of high-temperature superconductors does not contradict the concept of a TI bipolaron mechanism of superconductivity in these materials. Possible ways of enhancing T c and producing new room-temperature superconductors are discussed on the basis of the theory suggested.

show abstract

“…The above approaches, however, failed to determine the spectrum of Hamiltonian (1) even in the weak coupling limit [67].…”

Section: Polaron and Fundamental Problems Of Non-relativistic Quantum Field Theorymentioning

confidence: 99%

Translational-Invariant Bipolarons and Superconductivity

Лахно

2020

Condensed Matter

View full text Add to dashboard Cite

show abstract

“…Перечисленные подходы, однако, оказались не в состоянии определить спектр гамильтониана (1) даже в пределе слабой связи [64].…”

Section: оглавлениеunclassified

Translational-invariant bipolarons and superconductivity

Лахно

2020

KIAM Prepr.

View full text Add to dashboard Cite

О р д е н а Л е н и н а ИНСТИТУТ ПРИКЛАДНОЙ МАТЕМАТИКИ имени М.В.Келдыша Р о с с и й с к о й а к а д е м и и н а у к В.Д. Лахно Трансляционно-инвариантные биполяроны и сверхпроводимость Москва-2020 В.Д. Лахно Трансляционно-инвариантные биполяроны и сверхпроводимость

show abstract

“…Devreese and coworkers [8,9] were investigating the polaron complexes related to the excited states of electron-phonon system. In [10]partial summing of infinite range of diagrams for the two-phonon mass operator of polaron described by Fröhlich Hamiltonian is performed using the Feynman-Pines diagram technique. Renormalized spectral parameters of ground and first excited (phonon repeat) polaron state are accurately calculated for a weak electron-phonon coupling at K T 0  .…”

Section: Introductionmentioning

confidence: 99%